Preliminary results of entire pleural intensity-modulated radiotherapy in a neoadjuvant setting for resectable malignant mesothelioma

Impact of Neoadjuvant and Adjuvant Pleural Intensity-Modulated Radiotherapy in Multimodality Treatment for Malignant Pleural Mesothelioma

BACKGROUND

Few malignancies provoke as many controversies about treatment as pleural mesothelioma. There is limited experience with novel radiotherapy techniques worldwide in adjuvant and particularly in neoadjuvant settings within multimodality treatment. The objective of the current study was to investigate the long-term outcome of neoadjuvant and adjuvant pleural intensity-modulated radiotherapy (IMRT) combined with macroscopic complete resection with or without chemotherapy.

METHODS

We retrospectively analyzed a consecutive cohort of 59 patients who were diagnosed with pleural mesothelioma and underwent multimodality treatment including macroscopic complete resection and neoadjuvant or adjuvant IMRT between 2005 and 2019 at the Department of Thoracic Surgery, Medical University of Vienna, Austria.

RESULTS

In total, 59 patients (median age 59 years; IQR 54-66, male, n = 48; 81%) were included. Forty-seven patients underwent trimodality treatment consisting of induction chemotherapy, extrapleural pneumonectomy, and adjuvant IMRT. Novel neoadjuvant IMRT with (n = 9) or without (n = 3) chemotherapy followed by extrapleural pneumonectomy was performed in 12 patients. Median overall survival (OS) of all patients was 23.2 months (95% CI; 18.1-28.2) and 3- and 5-year survival rates were 33% and 28%, respectively. Survival was comparable between therapies including neoadjuvant versus adjuvant IMRT (median OS 17.5 vs. 24.0 months, p = 0.39).

CONCLUSIONS

Neoadjuvant pleural IMRT has been investigated as a novel treatment option for highly selected cases in pleural mesothelioma. Neoadjuvant IMRT was effective and safe in patients treated in a high-volume institution but showed no relevant survival benefit compared to adjuvant IMRT within multimodality treatment.

Is 18F-FDG PET/CT capable of differential diagnosis from tuberculous pleurisy from malignant mesothelioma?

AIM

18F-Fluorodeoxyglucose (FDG) PET/computerized tomography (CT) is a valuable method in the diagnosis of malignant pleural mesothelioma (MPM). But, some infections, particularly tuberculosis, are known to mimic cancer. We aimed to compare the FDG PET/CT findings of tuberculosis pleurisy (TP) and malignant mesothelioma and evaluate its role of differential diagnosis.

MATERIAL AND METHOD

We retrospectively reviewed the data from 85 patients (45 patients with MPM and 40 patients with TP) who underwent FDG PET/CT. All images were reevaluated and pleural thickening, maximum standardized uptake values (SUVmax), lymphatic uptake and accompanying parenchymal findings were noted.

RESULTS

There was no significant difference in age and sex between the two groups. Pleural thickening was more prominent in the MPM group. Mean pleural thickness was 21.4 ± 18.6 mm in the MPM group and 6.8 ± 3.5 mm in the TP group (P = 0.0). Besides pleural pathology, lymph nodes involvement in the thoracic (P = 0.0) and extrathoracic area (P = 0.34) and parenchymal findings were prominent in the TP group (P = 0.0). However, there was no significant difference in pleural SUVmax values between the two groups (P = 0.61).

CONCLUSION

Intense pleural FDG uptake can be observed in TP like malignant mesothelioma. For the evaluation of the pleural pathologies in the tuberculosis endemic countries, it should be considered that FDG PET/CT may have false-positive results. Evaluation of increased pleural FDG uptake together with the detected parenchymal findings and lymphatic involvement may help us to make more accurate interpretation of the diagnosis.

Trimodality treatment in malignant pleural mesothelioma - Ordeal or real deal?

BACKGROUND

Management of MPM is complex and controversial as there is a paucity of good quality evidence. We report the toxicity and outcomes in patients who received trimodality treatment for non-metastatic MPM at our institution.

METHODS & MATERIALS

We reviewed the electronic medical records of surgically managed MPM patients at our institution in the last decade. Dosimetric parameters of target volume and organs at risk were documented by the treatment planning workstation. SPSS was used for statistical analysis.

RESULTS

Between January 2008 and October 2018, 21 patients underwent surgery for MPM - all but 2 patients underwent extra-pleural pneumonectomy (EPP); epithelioid MPM was the most common histology. All patients, except 2, received neoadjuvant Pemetrexed/platinum doublet chemotherapy. Fourteen patients received adjuvant hemithoracic RT; ten patients were treated with a conformal technique at our institute and dosimetric data was available for analysis. Average time to start RT after surgery was 51 days (range 32-82 days). All patients were treated with a conformal technique using IMRT/VMAT to a dose of 45Gy in 25 fractions. Mean overall RT duration was 35 days (range 30-42 days). Grade I/II Pneumonitis was seen in 4 patients. One patient developed grade III acute lung toxicity unrelated to RT. At a median follow up of 25 months, 8 patients had died, of whom six died due to the disease and two died in the immediate post op period. Two-year DFS and OS were 58% and 73%, respectively.

CONCLUSION

In spite of the extensive surgery and complex hemithoracic RT, we demonstrated excellent dosimetry, toxicity profile and favorable outcomes in non-metastatic MPM.